Tuft feed control

Abstract

In a fiber tuft feeding apparatus the throughgoing tuft quantities are sensed, signals representing such quantities are emitted and in response to the signals, a tuft quantity metering member, such as a feeding roll is controlled by analog setting signals.

What is claimed is: 
     
       1. In an apparatus for regulating fiber tuft quantities introduced from a tuft feeding means into a carding machine; said tuft feeding means including a conduit through which the tufts pass and advancing means arranged in said conduit for forwarding the fiber tufts into the carding machine; the improvement comprising: (a) pressure sensing means connected to said conduit downstream of said advancing means, as viewed in the direction of tuft feed, for generating pressure signals representing the pressure in said conduit;   (b) signal converting means for changing said pressure signals into analog electric signals; and   (c) regulating means connected to said signal converting means and said advancing means for receiving said analog electric signals from said signal converting means and for applying continuous setting signals to said advancing means as a function of said analog electric signals to continuously and steplessly control the feed of the fiber tuft quantities to said carding machine as a function of the pressure in said conduit.   
     
     
       2. An apparatus as defined in claim 1, wherein said conduit is a tuft feeding shaft of a tuft feeding device for the carding machine; and further wherein said advancing means comprises a feeding roll situated in said tuft feeding shaft at the upstream end thereof as viewed in the direction of tuft feed. 
     
     
       3. An apparatus as defined in claim 1, wherein said tuft feeding means is a pneumatic tuft feeding installation and said conduit forms part of a supply and distributor conduit system of said installation and further wherein said advancing means is connected to said installation at the upstream end thereof as viewed in the direction of tuft feed. 
     
     
       4. An apparatus as defined in claim 1, wherein said conduit has a wall and further wherein said pressure sensing means and said signal converting means are constituted by a pressure-responsive switch being mounted on said wall and having an output connected to said regulating means. 
     
     
       5. An apparatus as defined in claim 4, wherein said pressure-responsive switch comprises: (a) a housing;   (b) a diaphragm clamped in said housing and having inner and outer faces; said outer face being arranged for exposure to the pressure to be sensed;   (c) a metal plate arranged in a face-to-face contacting relationship with said inner face of said diaphragm for moving with said diaphragm as a unit in response to pressure variations affecting said outer face of said diaphragm;   (d) a spring accommodated in said housing and biasing said diaphragm in a direction outwardly of said housing; and   (e) an electronic proximity switch means for emitting said analog signal dependent upon the position of said metal plate; said electronic proximity switch means comprising a body having a longitudinal axis and an end; said body being oriented such that said axis is generally perpendicular to a main plane of said diaphragm and said end is facing said metal plate and is at a distance therefrom.   
     
     
       6. An apparatus as defined in claim 4, wherein said pressure-responsive switch includes piezoelectric crystal elements. 
     
     
       7. An apparatus as defined in claim 4, wherein said pressure-sensitive switch includes a variable slide resistor. 
     
     
       8. An apparatus as defined in claim 4, wherein said pressure-sensitive switch includes a resistance strain gauge. 
     
     
       9. An apparatus as defined in claim 4, wherein said pressure-sensitive switch includes a capacitor. 
     
     
       10. An apparatus as defined in claim 4, wherein said pressure-sensitive switch includes a light barrier. 
     
     
       11. In an apparatus for regulating fiber tuft quantities introduced from a tuft feeding means into a carding machine; said tuft feeding means including a tuft feeding shaft through which the tufts pass, a feeding roll arranged in said tuft feeding shaft for forwarding the fiber tufts into the carding machine and a drive connected to said feeding roll for rotating said feeding roll; the improvement comprising: (a) a tuft quantity sensing means in said tuft feeding shaft downstream of said feeding roll, as viewed in the direction of tuft feed, for generating first signals representing the tuft quantities in said tuft feeding shaft;   (b) signal converting means for changing said first signals into analog electric second signals; and   (c) regulating means connected to said signal converting means and said drive for receiving said second signals from said signal converting means and for applying continuous setting signals to said drive as a function of said second signals to continuously and steplessly control the feed of the fiber tuft quantities to said carding machine as a function of the tuft quantities in said tuft feeding shaft.